Throwback Thursday 1989: the switchover to unleaded petrol

Something had to change, and fast.

Japan was the first country to introduce unleaded petrol in April 1972, and to ban leaded petrol, in 1986. In June of that year, unleaded petrol went on sale in the UK, and by 1988, it was available in 11% of filling stations. The first car to go on sale in the UK with an unleaded-only diet was the Toyota Celica GT-Four in 1987.

Meanwhile, the EU’s predecessor, the EEC, set new legislation for car emissions to make catalytic converters – which allowed engines to run only on unleaded – effectively essential by October 1993. This became known as the Euro 1 standard.

In the face of this new unleaded petrol, motorists were naturally worried – after all, lead was there for a reason.

“Around two-thirds of the 22 million cars and light commercial vehicles can accept unleaded fuel, according to the Society of Motor Manufacturers and Traders,” we explained at the time.

“There are, however, engines which simply cannot run on unleaded fuel. These are mostly older designs, with inlet and exhaust valves directed on a cast-iron cylinder head – and the lead is needed to lubricate the valves and valve-seats. Without it, they would deteriorate through corrosion and burning. To a lesser extent, very high-compression, highly tuned engines can’t be easily weaned of leaded fuel, either.

“In addition, there are power units that need modification in order to run on unleaded. A franchised dealer will tell you whether your car can be converted economically – or refer to the relevant Department of Transport booklet or a chart produced by CLEAR (the Campaign for Lead-Free Air).

“All that needs to be done is for the ignition timing to be retarded by a few degrees, thus causing combustion to occur fractionally earlier. Most dealers will charge £10-£20. On the other hand, dealers of prestige makes might charge up to £80 for turning an ignition chip around.

“Catalyst power units, though, are a different matter; these cannot accept leaded fuel under any circumstances, and damage will result unless unleaded is used."

So, how easy would the switchover be?

Autocar explained: “After what must be regarded as a period of complacency, a lot of Rover Group cars cannot take unleaded – among them all Metros bar the 1.3GS, about half the Montego range, and all Maestros and Rover 216s. However, current valve-seat development will ensure that all models built after this spring will be able to accept it, with the exception of the MG Metro Turbo and Maestro Turbo.

“Virtually all existing Fords can run on unleaded but, apart from the new 1.8-litre Sierra, they will need to be adjusted. Just the Escort RS Turbo will require leaded.

“The V12 cars will soon be factory-set for unleaded; fortunately for Land Rover, the Range Rover’s all-aluminium V8 needs no re-engineering before it can be retimed for unleaded.”

Catalytic converters are universal now, but they were almost unknown to the British public in 1989.

“Contrary to widely held opinion, an engine tuned to run on unleaded fuel and an engine with a catalyst are not the same. Have your car retuned to use unleaded, and it won’t pump lead into the atmosphere, but it will continue to emit carbon monoxide, unburned petrol hydrocarbons and nitrogen oxides (NOx) – all poisonous. These gases produce smog and contribute significantly to the acid rain that is having such a dire effect on European forests. A catalyst engine, in contrast, produces an exhaust that’s free of these pollutants.

“When pioneered by the Americans in the late 1960s, catalysts were downright crude – and proved inefficient, lacking in power and thirsty. However, much has happened to them since. Today, ‘clean’ engines are much more efficient. Virtually all catalyst Porsche models have identical power to their non-catalyst counterparts.

“The modern catalyst is a stainless-steel box measuring about 12inx9in and containing a mineral combination over which the exhaust gases pass. Although compacted, the metals actually have a surface area as big as a football pitch. And the chemical reaction to the minerals reduces the gases to harmless CO2 and water vapour.

“Because lead pollutes the minerals, just one tankful of leaded petrol would be enough to wreck a catalyst. With unleaded fuel, the normal life is thought to be around 50,000 miles. A catalyst for a small-engined car adds £200-plus to the asking price.”

So, how quick was the UK to take up unleaded?

Well, despite its growing prominence, in 1988 the fuel type took just 0.4% of sales. So the Government introduced a tax structure that ensured unleaded petrol would always be cheaper than leaded, with the difference beginning at around 6p per gallon.

“The oil industry has invested something like £400 million in making unleaded petrol available,” said Ian Berwick, director general of the UK Petroleum Industry Association, back in 1989. “So it’s disappointing that sales are increasing so slowly. They reached almost 2% last November, but that’s still low."